Specific Aims: This study will evaluate whether the case management and nursing, nutritional and psychosocial support service component of Washington's 1989 Medicaid expansion for pregnant women has succeeded in averting deleterious and expensive birth outcomes. Specifically, this study will 1) examine the effect of support services and case management on use of prenatal care, birth outcomes and medicaid payments, 2) explore whether the impact of these programs is greater in certain groups of women, such as teens, and 3) determine whether the more support and case management services used, the better the birth outcomes attained. Background and Significance: Despite their lack of financial barriers to care, women insured by Medicaid have higher rates of inadequate prenatal care and poor birth outcomes than privately insured women. Addressing the social service needs of low-income pregnant women has succeeded in improving birth outcomes in several small scale programs, and how is being implemented by a number of state Medicaid programs. This project will help determine whether these large scale, statewide programs can also succeed in reducing adverse birth outcomes. During this time of shrinking public resources, evaluations of the effects of existing Medicaid expansions on birth outcomes and costs will help policy makers decide whether to maintain or expand these programs. Research Design and Methods: A pre- and post-intervention study design will be the primary method used to evaluate the effects of the support service and case management programs on prenatal care use, birth outcomes and Medicaid payments. We will compare the change in the study's outcome measures before and after Washington's implementation of these programs in the Medicaid-AFDC populations of Washington and Colorado, a "control" state without support service or case management programs. The study groups will include singleton births of Washington and Colorado residents insured by the Medicaid-AFDC program during seven baseline and seven impact months. Similar analyses will be performed for subgroups of women such as teens, African-Americans and unmarried women. A secondary, cross-sectional analysis will compare the study's outcome measures among subgroups of women receiving different levels of support and case management services during the post-Medicaid expansion period in Washington State only. We will use Washington's First Steps Database, which has linked birth, fetal death and infant death records with Medicaid eligibility and claims, for the analyses of Washington's births. Co-investigators in Colorado will create a similar linked database for the analyses of Colorado's births. The intervention of interest is the support service and case management component of Washington's Medicaid expansion. The major outcomes include one measure of the use of prenatal care (percent of expected prenatal visits), two measures of birth outcome (birthweight and newborn length of stay), and four payment measures (Medicaid payment per delivery for maternal care, neonatal care, post- neonatal care, and maternal and infant care combined). We will adjust for potential confounding factors, including maternal demographics, prior pregnancy loss, preexisting medical conditions, geographic location, availability of obstetric providers and medicaid enrollment pattern in our analyses.